Keeping Tabs On Transcranial Direct Current Stimulation

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Monthly Archives: August 2014

Neuromodec presents

University of Florida: tDCS Workshop 2014

An intensive two-day international meeting dedicated on the design and implementation of tDCS in clinical and research settings. Update on 2014 state-of-the-art methodology with presentations and discussions on the development of professional standards for safety, validity and reproducibility of functional outcomes in tDCS applications.

We placed one stimulation electrode over the right PPC and the other over the left PPC (dual tDCS) and varied the polarity of the stimulation. We found that this manipulation altered visual localization; this supports the causal involvement of the PPC in visual localization. Notably, mislocalization was more rightward when the cathode was placed over the right PPC than when the anode was placed over the right PPC.

Jesse interviews Nathan Whitmore, creator of the open-source project OpenBrainStim, an affordable alternative to commercial transcranial Direct Current Stimulation (tDCS) devices. Nathan tells us how the project got started, how the “DIY-tCDS” community has grown, and how you can experiment from the comfort of your own home.

However, in all three instances,the skin lesions occurred under the cathode supraorbital regionat the end of the sessions. By separating the electrodes from the skin they presented small skin lesions, which resembled red burns, with small blisters Fig.1. The extension of the lesions ranged from 2 to 3 mm up to 1.5 cm. Lesions appeared after the second stimulation session in one patient, while for the other two, they appeared between the eighth and tenth sessions. None of the patients had a skin lesion before the start, skin disease or a history of any pathological skin disorder

The VR wrist exercise (B) facilitated post-exercise corticospinal excitability more than the active wrist exercise (A) or anodal tDCS without exercise (D) in healthy volunteers. Moreover, the post-exercise corticospinal facilitation after tDCS and VR exercise (C) was greater and was sustained for 20 min after exercise versus the other conditions in healthy volunteers (A, B, D) and in subacute stroke patients (B, D).

Conclusions

The combined effect of VR motor training following tDCS was synergistic and short-term corticospinal facilitation was superior to the application of VR training, active motor training, or tDCS without exercise condition. These results support the concept of combining brain stimulation with VR motor training to promote recovery after a stroke.

The Department of Veterans Affairs, in conjunction with the VA in Texas and the Women’s Hospital in Boston, are collaborating with Dr. Weisend and his team to use their tDCS system on service members who are struggling to live with PTSD and traumatic brain injuries.

“The way we approach it is not just simply hoping behavior changes,” Dr. Wesiend says. “What we do is we figure out what the most important thing to change is so that we can effect a person’s life in a positive way. For example, people with PTSD tell me they have terribly disrupted sleep. Traumatic brain injury sufferers may have a completely different problem. It’s like thinking of different disorders as having their own personalities.”

Join us for a cutting edge view of research into brain stimulation and cognitive enhancement. This event will highlight the possibilities and pitfalls in this newly emerging field: Can brain stimulation change our mind? ? Are there physical and psychological risks? Come and find out!

Join us for a cutting-edge view of research into brain stimulation and cognitive enhancement. Discover the possibilities and pitfalls in this newly emerging field: Can it change our mind? How does stimulation interact with behaviour? Can we improve the damaged brain? Are there physical and psychological risks? Join Roi Cohen Kadosh, Gregor Thut, Jacinta O’Shea and Gemma Learmonth to find out.

After six month of tDCS focused on my optic nerve and visual cortex combined with visual training, I have had marked improvements to my visual perception, especially in contrast perception and perceiving objects from afar. For example, if I am walking on the sidewalk, and another person is walking in the opposite direction towards me, I would not have been able to notice the other person until they were about 1 meter away. Now, I will notice people from 3 meters away. I can’t see them clearly enough to identify them, but at least I can move out of their way, if they’re in a hurry. Likewise, I can see oncoming traffic from 2–3 times farther away than before, which is very helpful when crossing busy streets. Another example is when I use my computer. I use a large Apple 30” display, and before starting tDCS, I would sit with the monitor about 3 inches from my eyes. As you can imagine, this was not at all comfortable, but I had to do this in order to see the screen clearly. After the first few days of using tDCS, I was able to push my monitor back and sit 6 inches away from it. Within two weeks, I was sitting about 12 inches away. Now, I sit 18 inches away. This is the first time in my life I’ve used a computer at this distance. Similarly, I’m able to use my iPhone at much greater distances than before 6 inches now, compared to 2 inches previously.

What makes tDCS work?
Let us start with the application of DC current and its study at neuronal level. While the electrical current goes through the scalp and cortex it encounters different mediums. Each time it goes through the limit between two mediums it leaves some charge behind. This is what happens when traversing the neuronal membrane, which constitutes the interface between the interior of the neuron and its environment. These charges generate a voltage difference, which makes the resting potential of the membrane either decrease or increase, depending on its sign, i.e. on the current sense. Therefore the neuron is correspondingly either more likely or less likely to fire. When applying an anodal current, the action potential thresholds of pyramidal cells under the anode application area are lowered, meaning that they fire more easily. Therefore this current, and its associated electrical field, is considered excitatory. On the other hand a cathodal current would present an inhibitory effect.
via Quick and Dirty Guide on Transcranial Current Stimulation.